Small -dimensioned coupler plug, especially for a planar broadband lambda probe

ABSTRACT

To make possible a very small and compact design of a coupler plug  1,  especially for use for a planar broadband lambda probe, having a balancing unit  6,  it is proposed to configure the coupler plug in accordance with the following features:  
     a coupler plug  1,  comprising a housing  2,  i.e., a basic body  3  and a cover element  4  as well as electrical components, which can be inserted into the housing and fixed in place, as well as a balancing unit  6  for a probe, in particular a planar broadband lambda probe, which is arranged within the coupler plug  1  or outside the coupler plug via a further contact element. In addition, it is proposed according to the present invention that the cover element  4  can be mounted over the balancing unit  6.  In addition, it is preferred that a primary locking device and a secondary locking device that cooperates with the cover element  4  be provided, the secondary locking device being configured as a fixing element  12  to fix in place at least one electrical contact  13  that is inserted in the housing  2,  and this fixing element also having support elements  11  that point to the cover element  4,  such that the cover element  4  only closes completely in the end position of the secondary element.

[0001] The present invention relates to-a coupler plug connector, in particular, for a planar lambda probe, made up of a housing, i.e., a basic body and a cover element, as well as electrical components, which can be inserted and fixed in the housing, and including an adjustment (balancing) unit for a probe, in particular, a planar broadband lambda probe, which is accommodated within the coupler plug or outside the coupler plug via a further contact element.

BACKGROUND INFORMATION

[0002] Coupler plugs of the kind discussed above are usually configured for the connection between a cable harness plug and a lambda probe, the terminals provided in the coupler plug being provided for the adjustment, the signal, and/or the heating of the probe. The lambda probe and the lambda regulation, along with the 3-way catalytic converter, represent today an effective exhaust-gas purification method. The lambda probe, which can be screwed into, for example, an exhaust gas system, includes a sensor for ascertaining the oxygen content in the exhaust gas.

[0003] The residual oxygen content is very well suited as a measuring variable and regulates the air-fuel ratio, because the latter indicates precisely whether the air-fuel mixture is burning completely.

[0004] In this context, the lambda probe generates a voltage signal, which represents the instantaneous value of the mixture composition, and which follows the mixture changes. The fuel supply to the engine is regulated by a carbueration system in accordance with the signal from the lambda probe such that a stoichiometric air-fuel ratio λ=1 is achieved. In accordance with the design of the exhaust gas system and with the conditions for use, heated or unheated probes are used. The lambda probe has other uses apart from motor vehicles, e.g., for regulating gas motors or oil/gas burners.

[0005] In particular, broadband lambda probes have a modular design and, in conjunction with planar technique, can be integrated in a plurality of functions. They usually have functional layers, which are made up of a porous protective layer, an external electrode, a sensor foil, an internal electrode, a reference air channel foil, an insulation layer, a heating element, a heating foil, a resistor or an adjustment element, and terminal contacts.

[0006] Because the broadband lambda probe is made up of the combination of a Nernst concentration cell (=sensor cell) and a pump dell that transports oxygen ions, it is able to carry out very precise measurements not only in the stoichiometric point at λ=1 but also in the lean and rich range.

[0007] Every probe must be individually adjusted. For this purpose, the probe has a built-in resistor (“mini-hybrid”). The balancing, which is preferably accomplished using a laser beam, is carried out by appropriately ablating the resistor layer that is situated on a ceramic substrate, thus generating a change in the resistance and resulting in a balancing.

[0008] One specific embodiment is seen in the fact that the adjustment unit, or the resistor, is arranged right on the probe. A further exemplary embodiment is seen in the fact that the resistor is accommodated outside, for example, on a cable harness plug that is coupled to the probe.

[0009] Heretofore, the balancing has been carried out by transporting to the balancing location the housing of the coupler plug without the cover element, the resistor being installed in the coupler plug. After the appropriate laser treatment for the balancing, the cover element was then subsequently mounted at a different assembly station.

[0010] To prevent humidity, contamination, or the like from penetrating into the coupler plug, and to assure that the appropriate atmosphere is present within the coupler plug, the cover element has additional seals. In addition, pressure compensating elements are arranged on the housing of the coupler plug.

DISADVANTAGES OF THE RELATED ART

[0011] One disadvantage of the design of the coupler plug depicted here can be seen in the fact that additional working and assembly steps are necessary after the balancing to close-up the coupler plug in a functionally correct manner.

[0012] In addition, it is necessary to separately manufacture a supplemental cover element along with a seal, and to make this cover element available in the area of the balancing.

OBJECTIVE OF THE INVENTION

[0013] The objective of the present invention is to refine an embodiment of the coupler plug that is specifically provided for a planar broadband lambda probe, such that the probe can be produced in a cost-effective manner and have very small dimensions.

ACHIEVEMENT OF THE OBJECTIVE

[0014] The objective is achieved through the fact that the cover element can be mounted over the balancing element, and it has a primary locking device and a secondary one that cooperates with the cover element, the secondary locking device being provided as a fixing element to fix in place at least one electrical contact that is installed in the housing, and this fixing element also has support elements that point to the cover element, such that the cover element only completely closes in the end position of the secondary element (the fixing in place of the electrical contact).

ADVANTAGES OF THE INVENTION

[0015] One essential advantage of the present invention is that the coupler plug proposed here in accordance with the present invention is configured so as to be of small dimensions, because, due to the compact design, i.e., the installation of electrical contacts in a basic body and the arrangement of the balancing element likewise in the coupler plug, the external dimensions of the coupler plug, which is preferably arranged between a cable harness and a lambda probe, are very small.

[0016] In addition, it has proven to be advantageous that the coupler plug according to the present invention has only a small number of parts. As a result, a cost-effective and efficient manufacturing process is possible.

[0017] Because the basic body is completely surrounded by the cover element, it is possible to seal off the interior of the coupler plug through an arrangement of sealing lips within the cover element, or an arrangement of seals in the basic body, so that the coupler plug is protected, especially from spray water and/or soiling.

[0018] This also aids in the latching of the cover element to the basic body. Preferably, a first and second latching device, or a primary and a secondary locking device, are provided. The latter is configured such that the cover element has latching arms, which, in the closed state of the cover, are in contact with the basic body of the coupler plug and bring about a latching there using latching hooks.

[0019] This primary locking device operates in two stages. In a first stage, the cover element latches such that it is held on the basic body. As a result of continued pressure of the cover element in the direction of the basic body, it is achieved that the fixing element embedded in the basic body is fixed onto the electrical contact element running in the basic body, for example, a planar plug sleeve, which is connected to the lambda probe. However, the fixing only takes place by the fixing element being pressed onto the contact element, so that the contact element and the fixing element have a secure connection. In addition, the fixing element is restrained in the basic body, which means that, in the mounted state of the contact element, the fixing element can only move in the axial push-on direction of the cover. In addition, support elements are provided on the fixing element, pointing away from the fixing element, the support elements extending in the direction of the cover element.

[0020] In the non-actuated state of the secondary locking device, i.e., the non-fixing of the contact element, the support elements extend far beyond the basic body of the coupler plug such that the cover element is only held in the first latching action of the primary locking device. Only in response to a complete activation and thus the proper fixing in place of the contact element, does the cover element also undergo the second latching action of the primary locking device.

[0021] This has the advantage that it is possible in a simple manner to check whether a successful contacting and therefore securing of the electrical contact element has been achieved with respect to the lambda probe, and that the cover element is tightly closed with respect to the basic body.

[0022] Advantageously, hanging devices are provided on the periphery of the cover element which make it possible to secure the coupler plug on another part, for example, using a groove-and-tongue connection, or, on the other hand, through hanging devices such that electrical lines can be mounted on the coupler plug.

[0023] Mounting possibilities are optionally provided for spray-water sleeves.

[0024] A further advantage of the present invention is that the aforementioned seals on the cover element can be injection-molded, so that they are arranged in a nondetachable manner.

[0025] To assure a constant transition resistance between the balancing unit and the electrical contact elements, a solder connection is provided.

[0026] The cover element is advantageously made of PBT (polybutylene terephthalt) or equivalent materials.

[0027] A further advantageous exemplary embodiment of the present invention can be seen in the fact that the cover element is configured so as to be transparent. As a result, it is possible that the cover element can be mounted even before the balancing, because, if the cover elements are transparent, the balancing can be carried out through the cover element using a laser beam.

[0028] Further advantageous embodiments can be seen from the following descriptions, claims, and drawings.

[0029] The following are the contents:

[0030]FIG. 1 depicts a perspective view of the coupler plug according to the present invention, having a detached cover element;

[0031]FIG. 2 depicts a rear view of the coupler plug according to FIG. 1;

[0032]FIG. 3 depicts a top view of the coupler plug according to FIG. 2;

[0033]FIG. 4 depicts a perspective view of the coupler plug according to FIG. 1, but in contrast to FIG. 1, in a cutaway view and having a cover that is mounted in place;

[0034]FIG. 5 depicts a cutaway view of the cable harness plug according to FIG. 1 having the cover element in the first latching position;

[0035]FIG. 6 depicts a cutaway view of the cable harness plug according to FIG. 1 having the cover element immediately before the end position;

[0036]FIG. 7 depicts a cutaway view of the cable harness plug according to FIG. 1 having the cover element in the end position.

DESCRIPTION OF AN EXEMPLARY EMBODIMENT

[0037] Coupler plug 1, depicted in FIGS. 1 through 4, is the type of plug that is made up of a housing 2, which is composed of a basic body 3 and a cover element 4.

[0038] Arranged on basic body 3 in a retaining device 5 is a balancing unit 6, which via electrical contact elements 7 is in turn connected to the lambda probe, which is connected via a connecting element 8, or to the plug that is not depicted in any greater detail in the drawings and that is inserted into coupler plug 1.

[0039] Electrical contact elements 7 are made of metal strips that are shaped to resemble printed circuit traces, the strips on their one side terminating in the area of coupling possibility 9 (FIG. 4) of coupler plug 1.

[0040] Balancing unit 6 is guided by guide elements 10, which are mainly arranged on basic body 3, and it is held in position by electrical contact elements 7.

[0041] To prevent the lateral shifting of balancing unit 6, support elements 11 are provided perpendicular to the longitudinal extension of balancing unit 6. These support elements 11, as depicted especially in FIGS. 5, 6, and 7, are configured as a part of a fixing element 12.

[0042] Fixing element 12 is provided as a secondary locking element and has the function to hold in position an electrical contact 13, which is arranged in housing 2, and which, in particular, is connected to the lambda probe.

[0043] For this purpose, fixing element 12 in its cross-section is preferably configured in a W shape, enclosing electrical contact 13 axially between its two arms 12 a/12 b, in the assembled state (FIG. 7).

[0044] The secondary locking element, i.e., fixing element 12, is also configured such that it preferably forms a single piece along with support elements 11.

[0045] In the not yet assembled and fixed state of electrical contact 13, as is depicted in FIG. 5, support elements 11 extend far out of housing 2, so that cover element 4, which is mounted on housing 2, can only be fixed in a first latching.

[0046] The result is that, when the secondary locking device is not activated and therefore the fixing of electrical contact 13 is not functional and therefore the positioning of fixing element 12 is not normal, cover element 4 does not close (see FIG. 5).

[0047] Only as a result of the correct end position is it possible for cover element 4 to adopt its own end position.

[0048] The secondary locking device, once assembled, can no longer be detached after being locked, without completely destroying coupler plug 1.

[0049] Advantageously, coupler plug 1 has on its circumference grooves 14, which make it possible to insert a coupler plug 1 into retainer supports provided for this purpose.

[0050] In addition, arranged in basic body 2 are retaining and fixing elements 16, as depicted in FIG. 2, which make it possible to arrange coupler plug 1 on electrical lines 16, as depicted in FIG. 1.

[0051] For this purpose, retaining element 15 is configured as a clip, so that coupler plug 1, when the retaining element 13 is in the open position, can be plugged into a cable phase winding, and the coupler plug can then be closed as a result of a further motion.

[0052] In this way, the opportunity is provided to mount the coupler plug, for example, on an engine (support).

[0053] Due to its small external dimensions, it is also possible to accommodate the coupler plug in a grooved tube. 

What is claimed is:
 1. A coupler plug (1), specifically for a planar lambda probe, comprising a housing (2), i.e., a basic body (3) and a cover element (4), as well as electrical components, which can be inserted into the housing and fixed in place, and a balancing element (6) for a probe, in particular, a planar broadband lambda probe, which is accommodated within the coupler plug (1) or outside the coupler plug via a further contact element, wherein the cover element (4) can be set in place over the balancing unit (6), and it has a primary locking device and a secondary one that cooperates with the cover element (4), the secondary locking device being provided as a fixing element (12) for fixing at least one electrical contact (13) that is inserted in the housing (2), and this fixing element (12) also having support elements (11) that point to the cover element (4), such that the cover element (4) completely closes only in the end position of the secondary element.
 2. The coupler plug as recited in claim 1, wherein the cover element (4) is transparent.
 3. The coupler plug as recited in at least one of the preceding claims, wherein the balancing unit (6) is supported on the housing (2) by holding-down clamps (electrical contact elements (7)) that are configured in a spring-like fashion.
 4. The coupler plug as recited in at least one of the preceding claims, wherein the electrical components are plug-in contacts (18).
 5. The coupler plug as recited in claim 4, wherein the holding-down clamps (electrical contact elements (7)), that are configured in a spring-like fashion, and the plug-in contacts (18) are electrically connected to each other.
 6. The coupler plug as recited in claim 5, wherein the holding-down clamps (electrical contact elements (7)), that are configured in a spring-like fashion, and the plug-in contacts (18) make up a single piece.
 7. The coupler plug as recited in at least one of the preceding claims, wherein the electrical contact elements (7) and the balancing unit (6) are electrically connected to each other by soldered connections.
 8. The coupler plug as recited in at least one of the preceding claims, wherein a latching device (12) is provided between the basic body (3) and the cover element (4).
 9. The coupler plug as recited in claim 6, wherein a first and second latching device, i.e., a primary and a secondary locking device, are provided.
 10. The coupler plug as recited in at least one of the preceding claims, wherein hanging devices are provided on the periphery (17) of the coupler plug (1).
 11. The coupler plug as recited in claim 10, wherein the hanging device is configured as a groove (14), in which a tongue engages.
 12. The coupler plug as recited in claim 10, wherein the hanging device is provided to receive electrical lines.
 13. The coupler plug as recited in at least one of the preceding claims, wherein a mounting possibility is provided on the cover element (4) for a spray protection sleeve.
 14. The coupler plug as recited in claim 10, wherein the hanging device is configured as a supporting and fixing element (15) for receiving at least a part of an electrical line (16). 